docstr: Check whether the word is in the vocabulary.
          
docstr_tok: ["Check","whether","the","word","is","in","the","vocabulary","."]
code: def contains(self, word):
      """Check whether the word is in the vocabulary."""
      return word in self.__vocab
  
file_path: PaddleHub/modules/text/language_model/lda_news/tokenizer.py
label_desc: Use image node_id 4 for calling the LACTokenizer obj's underlying member method code with example usage: obj.contains(word) and returns: unknown